Core B plays the role of the traditional Data Coordinating Center in a multi-site research project. As such, Core B has been designed to provide support to Projects I-IV in three broadly defined areas-Data Acquisition, Data Management and Communications, and Data Analysis. The specific objectives of Core B are to (a) facilitate acquisition of project specific data for Projects I-V5, (b) develop tools and procedures for ensuring and monitoring the accuracy and confidentiality of all collected data, (c) develop tools and procedures to aid the Principal Investigators, the Executive Committee, and the Scientific Advisory Committee in providing scientific oversight and administration of the Program Project, (d) facilitate communication and sharing of data among investigators through state of the art computer networking, and (e) provide statistical support and analyses to investigators in the evaluation of the Project hypotheses.